SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34d29c7b8248b90bedc5c646e6266d357e270e9abbaf7d31ae685820e7f66446' 
  AND token = 'vFmylqfoHZIpoMdi7wuyHbuIcF7Zixm4Frzu43N6y4k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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