SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '19e1fef170313fde12e8cc353da3327ae83e10ac7d015c8b52ffe8eadc1177a8' 
  AND token = 'Eo4XNjkXRGxNarQ/fyFUKILB1eyubbO6//lI09iDdns=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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