SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a3bcbae0e73aebdc7b7017380cb58c5188dc7222febf35a6289f42e718fa711' 
  AND token = 'QZtk6xLRCjgxOiLELzIurS9ZZddsva6kiP0FPyPGH0k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}