SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e8d4dbfc5ecb436146c17c8b6b5c1677cb8c45be030159e2cabc532b92ee2873' 
  AND token = 'I08tghjRfbF4gvOiwUAIHtsdKyyRX8rV+/fD1VCnkmw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00072

JSON explain

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