SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '926e0bbee6f904b982ffc416b1bd2c23c6246d7d732325d857a7ad745bba2f91' 
  AND token = 'bWLaUcYqGl/Jbx8bExAQYoEZZkcDQLKVxuLEPvJaAdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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