SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f19674d7ca22c16bb5a635d907781d1753feaa30cea26f594475e5bd695bbb1e' 
  AND token = 'HpTxxWhfxL1evS+EbgGCleDxhH6tp4hffj3kl79KrZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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