SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73d560e0d257b62f7100c187a19f9dc0cd048d500e4dc9b34e2d70cfa604faff' 
  AND token = 'PbspqWjHX05bAhlCj9GzUvpN8uOftagnshBCxU34y68=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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