SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '71c2fe597c814239307dbdae9b9a6ae3b9cb786549786f6e82ebe03b709f6a3a' 
  AND token = 'MIbxZwPeaPuhbDkyr3Qf7eLfOUZoAr0itUnZpI81l3o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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