SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a6d2703371c0968388535725c2130c86ecd4d7ff82561a18caf9ed97aee7d1b' 
  AND token = 'Gm1nXT4ebgIb92f+L0BpBQu9pJhJ43dwK4GgMHrmKHY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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