SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '05f635cfbdd416bcb97656cf0d26cff98cd35634d14e4e94cdbdf34ca8e14348' 
  AND token = 'flXSKXfLUAm1zWLoZravLIzY9xONmczygE4UzHUswaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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