SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19684f0b0a56b32b772bbab1f134966603145ae1863f92419af4945bc4432ec0' 
  AND token = 'CGGZlUJlKSmqr2nZlPhwVck9zcgtzqmGxy6ysfNpVqs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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