SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7abbbe1c85df8d350cfe65f5386eb3eeb6bd19cb0b6a3d92d559eca1e03ea5c6' 
  AND token = 'IItYzR9p5PIhpycPds9SYhxBAKMIqqI9+K7BKzJ2CRg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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