SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15fd4f29ec5e9a4b3dbab3fe94f6105f02253967950a57825bb7e9b5a419eb62' 
  AND token = 'KYnl9iLXZ73+ilvvkObd8K++J7yUU6XTChOeNJAoXAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00053

JSON explain

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