SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9da396c49185f8a94165e5e09bff5e6c5e81bcccfea5860398c7cd28302d7a5b' 
  AND token = 'C68R+F3W3RIj/nrcnBFDWcwgW2E9BRpKNkE+zt0gH/o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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