SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f84b2cd96b8090419c4e198e437038739792c1351782840a5c9490f22ac8f17' 
  AND token = 'zhZ0blATkoswMg1tg/Xn5vqQ+gr9fGCdzyiKp02OoYs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}