SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '207aa5060535cbf698fdd8aa15d14c2a7751ada37bda620cda9fd2a544eefb26' 
  AND token = '0GdYedmOFlfJ7cseTx55eFTZQKNQUN1WgpteajzxnfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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