SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fba3d21a41b7e1819fe1be9747920fff8acece5cc309a3cee34103b79ac839e0' 
  AND token = 'MdzzoHQl+BZ9wMUY8WvbuRR0+KJmnKprft76/a+DSww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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