SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '58b60da092de92a8b9009be01d644b37ca8cd9a3d9c928a6579461f34d9128e6' 
  AND token = 'iZKfIbvP+YjJJzOnNpVjkDi0Czp/no01NFmbxT4owkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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