SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '689322b9eb14e7f63e298d8c564fae58159076530dcac3cbac342067ac00550e' 
  AND token = 'JC0d382YCxFEr0cVWTQBBd8MlA1HvMpJ2itQrgQ5Y2Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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