SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0447a35454a8b75e2e9aaca3f90b3674258d0be83e6a2d489d9f778398ae399c' 
  AND token = 'aToXQVezVCTRWvTJGOhPqxQSb6sKx4vQfVOQBB/aTww=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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