SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3759c9bd1ca03f67e2a9f8d1cb75ea295a9ef968cb98a7b4c8ac3ee07d176279' 
  AND token = 'HZ4ejICFH6d8YT6H9I16scm6Tj22QVPZgnVINQoztrk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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