SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8474aeb7ce707d4c239a1c5a8fca34067dff7d5cebf560460da4f63911145e30' 
  AND token = 'JU9xLBbCJkAV08k0VlB2v8OQS8KWUJVGP2fO9hTZ9r8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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