SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ea33d1aefb3e7948869777f1659a8d33d8269841f3aa0915720b38db51525ea' 
  AND token = '6OOID+GRVV98wwt0OCoPhkzQs/wSOv0JoEeRnU2xfug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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