SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '582699122329833cdc24939b4c927a75e99f50b61262612132a619acd02eeca7' 
  AND token = 'cAXtts7KElu4jbhdThfoxcEzAplU+9QDvnoiGtOW7pc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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