SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f168632e9ef5b0f629c5cf781fe6145328a6f6e4c48da2e5327a6fdb10cfdb9' 
  AND token = 'hwBmdqv1XmvpFkq5zQ+Wfl4p9zGaj7jQDSSrPan8ILE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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