SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0c9a1fdfdb784ad8d4813d0831a61f3ab56bbcb84a867a73dfbdbb0d14f0c72' 
  AND token = '8JoWWpH/5Iib43dtQL4EMJLIqgpwrx3sy902hj3pPcY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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