SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8dc414e55e111dbed203ab10eaf9276cfa6b96257864f465b2057ae0dd16252d' 
  AND token = 'n/tgm7s+EqWSqK+KANpdavPtxIrMA6+Jhdq+jShyenI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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