SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6885f708eae1c7ce58fd230569930d30b1864307f9c672ef099b3a8a16c9d3a' 
  AND token = 'Qq7M+Ytbs1AkoNN/IbSC3snBvXqfyUlcBfJTiYOi9y0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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