SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed58273812d18c25c88084a6b720aa6f77cf3d0d476ddfb7fe5902a15a215441' 
  AND token = 'L1YM+EV5CRP/BOWkoaBlOzJ4MV4uLKbhxuihZAntwG0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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