SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e10638203147a45e3d60c97d9073d972fdc5c9bf7088c1d0c5498ffc5593f2f1' 
  AND token = 'WPDgCby7wZ9ct6KjzwOt/YajWv75msokk8JiQzDYbiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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