SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2e60e5b10a4b7aa2fc8bece462a3a1b250504d90c5e8767a96c36ad9ff4a6524' 
  AND token = 'FBbnGK/5oIA7eyzgFXw56pOhIlFUg0qZEHypGQUSUgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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