SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64959179b2c8f700c301ac25cc82da826079abcda4387efd4dff194feb09211c' 
  AND token = 'vp9ulV6/RnXB7PWRFwzkUn+P11BqOIlVJtJ98ky7E3Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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