SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64b469197959de375ef67cd6a636f740895a97966d93f35f5316d0d5367f12cd' 
  AND token = 'kGgYKfMeVPozLWcP1ZnpZaCZJwM/2CwCDogIsT9E5Q0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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