SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a418a50f10b80fa43b6b3b0492c087ef029affcf633512d2844bb64caa242ca7' 
  AND token = '/ScgtiRFMgpUvvi7/LMRx3y5WqOTFr1sEGwCXIzAS14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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