SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0c73d508d7e6bedebca34dd39b86e7fa48ff9e42fba026a7c881d3a3e3608d6e' 
  AND token = 'c6KLr8VnRjzNUyElKKhJHPTtrjqzpl+M2/yS704ECYo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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