SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b96a7202cd1a894a3704dbdd93320251ceb776e99eb8da41d21ca7a67191ec4' 
  AND token = 'lYqOi03BWJm3Q64bmJmZLzlzw+PFRRXy63dl5glfXEY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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