SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e6eba260fbbe8528226e2c2fa968850e9262b4df99c801df318e5f552a1b1d6a' 
  AND token = 'Q4vUMhWYhAzsCJJwVbGHdqWsXDL4w3xUJsx9uiPIVVA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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