SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '557268f8a9d435d2c71e75f8ebff369d30d4e3cae36d9e98c01593740a4bbbb2' 
  AND token = 'nFRNOI5F5/KZlDQHgqPv9LS9LKNjlUJrvHUC1VfeszA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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