SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8b82278266dec4396fe7e479d2715e5681d5f660bfbac64117d9b75ad6374d25' 
  AND token = 'rgVqCvXKcyinmyNuMlrBkT+qz9bGV2mqRs3ceTQC4oQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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