SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73b263f06c3c673ee2d23e8ab495ff4c7e2f977e11652a861957608ea9c18cd6' 
  AND token = 'PzmK0f2/krELGYOZTr8TclBmftxp86k5vLnFGmL2jf8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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