SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a4e1b58505ff31ad090f32471ea92eea72af4b4d46289f159f22dc964d8d336' 
  AND token = '3OI6tIJIh5Q2fQ3HVLJBRFb+1s1H1WRbs1vMQmKXZb4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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