SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d3c980b70cb219180286de25ffe3ff48265e739560569ba1d1d6928bd7297b6' 
  AND token = 'QbHkKGSmgx7dF4GIynJzVejxfoyrcpZkpJ9AvhBJ59Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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