SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b37be1ad0225f1a024f9cea8738e155f0cd71244ad9f4d19cf4cf145ffcb9f1' 
  AND token = 'izb4JQpJjKDNmkwLnDCwhJcYt5OVj7qZZ8zXpggDt+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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