SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68765d071c01a31813e98300339e3cdfe0b9e4c954f23ead270cb05ad86886d8' 
  AND token = '/e0j/hrBuCjd6pIbdHT3Dyt91ui1L++R6StPQ4XkBK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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