SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'ec0857e86df9139330a6e7d073bd86609def6f7a2737ee77a1be8f18ac7822c4' 
  AND token = 'g+p91oWIXWuk5syZJdg7lZ+Hud0IBgJG4bji7GMWEl0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00211

JSON explain

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