SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a1ee431fc0f049c0b5768007c88ef197b03ca2a5bf5930e3aa48f83eb66a6ec' 
  AND token = 'OMFoXKfZPNw9P9bGBRT2muzMwmH0BQFRFpQJ7o8oMk8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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