SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f156805258a71006f0049fb80410bfabf06fa5c209847be11ac3df99be586ee' 
  AND token = '6CY2dD8308FkL97lw0syqjHTjhOIDK0SR3YZbiD7vjc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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