SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef3bee7791e254f83457873d08e058171e6b37affdc0029a50baad63d2ae7038' 
  AND token = 'Jn6c/6mvQ9uupMK7IFC1enA1VIjDKoRhp5e1am5ZedE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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