SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '12d4b7402d0ace0f68504d5cf9fe13967561c7e5e75f9289e580e76cb424ad39' 
  AND token = 'KUkaAq0ZcGUoUp2/n1s0SSUc7n0KTfOdewc+Eeqgz1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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