SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1faad679a135a06182bf92b1194513fe5f11b8b29ee13ef65852813fcb7069d8' 
  AND token = 'rkl4XP3DsC4C475H5MDKZOWDBZ+jzPiBlXraCxg8qVo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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