SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0afd539c7a692569adc65eaef6ac81e7cedeadd97593d0daa3b824104236e85' 
  AND token = 'EmnZHLXHYjCkPufuAJNsfmUYncL+q5Q/wRK3gELqTVk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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