SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3a97c185c2946ada1bf76d5a919d14112642cb52fc0ee516478937f0b0d5437' 
  AND token = '4i8LB8owxF2uDEDzuafKayOv/SBWo0gyZkRU73RQN6Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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