SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35bb7382dfa21f651bfcc7c963a53922198ec25477189a8336b98f9b395105a0' 
  AND token = 'Qywizjhu81nkHvgRgiY7vGxwTSpBzI65gIgRO0jHTPw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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