SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01fd64e5382c0f5da6898ede103644d0ac532aa4486a297e2ff66e96bc3f052d' 
  AND token = '2PoPgUEvt2wMFbjHOgYiri7G8DUAvzqkljgmekd3Rcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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