SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e380fe8423457590c1b8c0e095b687828caf36bf0cdb7fad2d70d35e42fc83d1' 
  AND token = '2L7A1jhXOosr9lgzzZPP6+HZcotuGReYWgQwmqC9p3c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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