SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27598a090496d26b3154f48cc8565dd79483ac3c122fc3f674c19f6a8574db1a' 
  AND token = 'Mopx7nBzna/nWGoeeIZfNd3sHdmmTI5REKqT/mG630g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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