SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e507faf1658433b282525300c009e6f8b5e0ddac75460a572f3dfd0b34100432' 
  AND token = 'fqpXNqZmEagKUvhxH/o2GGOuDVC2mqtlmyUFzggLzAM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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