SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c12cd81c533eec1cf2e3c5ec52f6831f4b90f40187688b65abc808bdb10782e7' 
  AND token = '5L9IPW/lPO5Ybfb73yljkSpZ915HC9lSDayabyWjeiw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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