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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ddd00e921da3ca774cbf9d7a680b61e46f1326b4d43f217f21ccf2c07e98284c' 
  AND token = 'Uj3Ahnk/HEgwWncXR4AehviXV9hb+HgkW5Q/nbGwO6E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}