SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a5cdb451f0ef0c90cf76e7368fe9813a04dbd8325e67ab921cdd44b47b71ef6' 
  AND token = '5zvrnXATH9emiGlkzZrAwFMxMb0h7tPfZTpJoJUC5bQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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