SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f677fc9e8860208bde46f96b16c7db7464cd31b476cacceeea25ec761ef56feb' 
  AND token = 'ciAa51cPO127nR/S9IZcdNpUbrpsNLYd/1ypDxSVliE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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