SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f9153aa186da6e59fe85838f50cc5bbdf67215106057076e7778d0742d3ace6' 
  AND token = 'gwzZPc9RdZNBcpleM2DmwOd5wFKswwdWeeCekaPu7lk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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