SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3833f2545495f169e9fd5bd8b26391cb18c0a2de20fb3eb9e6dc4a4bc9581ae8' 
  AND token = 'M4gvAeKqOSJBXgCWgLLPZkhwYq1bw0GJpPgY2iKsA3k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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