SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e34057e1f30c11fc7e59e63a70816405efed9fcaf6a2a953868caa928581230' 
  AND token = 'OFD9DZiUzpWCKnI86IBqYw1pFIvoPmyhvxiYJ0dbzOQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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