SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2034f690c949219b38f916ffd7907b9874056cf4bb57beb9053244247178eee6' 
  AND token = '7D7o2+zB/DLtUhEEobOPvSPuoKnk/frlLBZ5ckA6fCM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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