SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2fb733f0644ff2bdb90587f16e4e19eb751ae313c1756a218a259db84c6979f7' 
  AND token = 'Nfw2JN9zwMLlfowRDgJvZxHpM6/6jNOG45u03JY3FKw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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