SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8a05348af487ae44ed317db1e50d197678d9e179cf5700932663bb766149d26' 
  AND token = 'lLvReBPDsRL4nICCohCi6qabQyppHV48TB0gjQLQ9Dg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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