SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caf17bf45c8eb7a49b01ba409cc728e48a2301ffacddea8b2185026f16337852' 
  AND token = 'kVbrtd9DSKS48RghoCfsXEzNXlVOwZOG3lL+16uVLWU=' 
  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"
    }
  }
}