SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa9b255b9fea095a661b973316482963201090fb80197daa4667bce8aa48359a' 
  AND token = 'UCgKyRrRX/rXPAyTKadpkSz6EItHvX6yAXb3H93wkdc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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