SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80235b769deacae452dd50a1326b1e9ae9780eace1d0dd54e4a746e280d36787' 
  AND token = 'oeS8fMpt7a31xiWZAUnUmekNify76Jg56SIiThDrsZ4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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