SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '550ce19f19f65a190c58bcef1fa89d19c63eb86f6962d9dbb76dc4ccb222c073' 
  AND token = 't2nEeqZl7LFQvgFlWWjeI0xt5ozNJncEf9bu/kmYZyE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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