SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd0556c9fbd078c8de720254786868b2c460329e687a2f6615fdab2294d48b63' 
  AND token = 'cLL9XSoBZYQmCX0gaFw7Cp52+SGTlOOzVmpVZbZzmew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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