SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1a280c60531376a22b66f642129d2dc418e2824b5be9692f3e07becec54bb65' 
  AND token = 'E2kZ6Mp47RYHze90s4jdgRZ8EmXeZnSrLchOYYuKuQ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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