SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9382af823e926a44ea6e3d502e4fde44cf71139f7dd12866832ba2d985d58227' 
  AND token = 'vK/uLWKfPn4ID+uIpLqobGK0BMhGkJcsJFPPRqEJYX4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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