SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '893353c478280fe62935a1ac4e31ceabbb318de1221ace60e95e835000d81d2f' 
  AND token = 'Mp/gXbpVHiTv9dpAu6ifqziM86eFQoe+fxmxqOQr5XM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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