SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b83083f5219fb55ad9c28713cdcc99b2114d6c7f3d249534bfd036f4081b6e0' 
  AND token = 'TLV1aQdO2m9QWGQJjhiqK+eFG1dm2HtX3EWzK9wY0SA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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