SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7324af5098f3ece395ac43c892cfa0d6241b7a1748728eb748d800d445677d69' 
  AND token = '6w6QzQSwjF3QKTODjFaE/2KvbRgGJND/2lpfAPrhebM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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