SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '85784c6921219517b208ddab0423554f785755d59df70be5cb3053564e1417b0' 
  AND token = 'lt4FGo4i9kIKCRGm1TF74h9I7ugCRbnkUkZJQqnhukE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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