SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c719ca2ee43d95c6246d2471b55d92e6dbf5d628b42f48d60e239d7418ef1931' 
  AND token = 'hLYqBiD4Xp2foQsAqJcJY2q+yMvbMF7/xrJyN+UoQ7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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