SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd3da418f9e06933080e6847c379c40b296b5886427351355f08c1579b3b0d5b5' 
  AND token = 'GePMQ4/fnGPCVxiZhgsVYbmOvgSiNqymzGSDOCXjjjY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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