SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98add5a3608266a3b1830f280af7c47a9a0f9b70d4c9a9e4d6601fa75b55cca8' 
  AND token = 'LGgYNhMjXO/3KYhNDkP9b9SZZEJ+ITslesZY322m+hc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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