SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '019c0b2ae17e85d3454447439ffda82e2cb02ba4b78fa3a3477c6d79d8d604e6' 
  AND token = 'qpV3HiZbOKdqqdXjtQXWJdu5MjMnkNQDWGLbM58OTUs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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