SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b311545a97fe97dee5affb864670128133d7707d9b8ac2834f865062f9bcaf1b' 
  AND token = 'ntcdGbx0tx0FO8tWMniETpPheMBwnU8VSBgoofKnGh8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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