SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c5eb3cf9bde4c49a8de3eb1fba480686e041ff7419705b32c359570a081516a' 
  AND token = '7zZzqw6oaS1arJWE9mT3J25UPD+TAzYxDUe5NaIJUPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}