SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7a25c0cf481ba3b67c1a907b1f5c768f2540793d089bc0115f2c578c25d9b42e' 
  AND token = 'G+mzfv53GiR3k20xB3KLY/oUVXllqQBuzFX3DkPMwf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}