SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b3004c60c038955fd4d75145ee3a12284b7c8ecf18dafc050b67660d9961e019' 
  AND token = 'aEmjyVaCXo0il3GWQfEDH+7+uT1xXAhLkZIGNMzXca0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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