SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6877c5b8dbddf48e4f9c3041c2bcf201689bc26d51be60527b3123fd8aaeef9' 
  AND token = 'ZTxm1FNHzF/x6tgYybrM2QUa4CO7LvNxnbZ0DDX+9kc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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