SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f7bd10ace1bf64b0c875dbe3fc07ffddde281b63033c5f5f2345a717bbde091' 
  AND token = 'fIDE0tHMBsrSX6vJd1iKLILGU+M9zh9LdQVGnueIiw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}