SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2523fa089e018784b9ac1248422cca6f7e00df424d830284943c2a5b76ee783' 
  AND token = 'tvgl8ix09VWdsGPYiuz2mqJHcWl0qbsjNfAfybcDT2s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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