SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9df880c651b5273ad20205a253394e37c6b8203651157c02ed7c4fd69a95d470' 
  AND token = 'ZXxFwIWanK/wAZGUpqPBvr8Re/o5bBScxugr8/dYb24=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00011

JSON explain

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