SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '04856f3c78bb4846235d43569a04589ed40fc9d633f032e70eafa448988f3e83' 
  AND token = 'hfhEHLAoavaGWuIVS33Dpp7Pk9KkZlxmk0khlZtdWfg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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