SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'afeaafb7069c6305934363fce2a9ffea10e5c49a786adc8020825b417914eadb' 
  AND token = 'kBnhJkDokWTpLi9ScRr995jvkTj8sF5NWEgxfnbdsTA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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