SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3eebcff78da7211aa6f091a42fd28e50f517c60a0ada87ba6c5aa9e0b2794ee' 
  AND token = 'etUTDXO8p/H/PYxrV9hNVZKClY3kiA5hduxkIbE7t/Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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